TWI790200B - Epoxy resin composition, half-cured epoxy resin composition, cured epoxy resin composition, molded product, and cured molded product - Google Patents

Abstract

An epoxy resin composition contains an epoxy resin and a curing agent, wherein, the epoxy resin contains an oligomer including a structural unit selected from the group consisting of a structural unit represented by the following formula (IA) and a structural unit represented by the following formula (IB), the oligomer contains a dimer including, in a molecule, two structural units represented by the following formula (II), and a ratio of the dimer in the whole epoxy resin is from 15 % by mass to 28 % by mass. The epoxy resin composition is used for a half-cured epoxy resin composition, a cured epoxy resin composition, a molded product, and a cured molded product.

Description

Epoxy resin composition, semi-hardened epoxy resin composition, hardened epoxy resin composition, molding, and molded cured product

The present invention relates to an epoxy resin composition, a semi-hardened epoxy resin composition, a hardened epoxy resin composition, a molded product and a molded hardened product.

In recent years, the miniaturization and higher output of industrial and automotive motors and inverters (inverters) have rapidly progressed, and the characteristics required for insulating materials have gradually become considerably higher. Among them, the amount of heat generated by conductors that have been increased in density along with miniaturization has gradually increased, and how to dissipate heat has become an important issue. From the standpoint of high insulation performance, easy molding, heat resistance, etc., a cured product, which is a thermosetting resin, has been widely used as an insulating material used in such motors and inverters. However, in general, thermosetting resin cured products have low thermal conductivity, which is a major cause of hindrance to heat dissipation. Therefore, development of a resin cured product having high thermal conductivity has been desired.

As a cured resin having high thermal conductivity, a cured epoxy resin composition having a mesogen skeleton in its molecular structure has been proposed (for example, refer to Patent Document 1). The content disclosed in Patent Document 1 is as follows: a relatively hard structure represented by a structure called a liquid crystal skeleton is introduced into the molecules of a resin, and liquid crystallinity or crystallinity is developed by utilizing intermolecular stacking properties, and Suppresses phonon scattering to increase thermal conductivity. In addition, the epoxy resin having a liquid crystalline skeleton in its molecular structure may, for example, be compounds disclosed in Patent Document 2 to Patent Document 4.

In addition, as a method of achieving high thermal conductivity of a cured resin, there is a method of filling a resin composition with a thermally conductive filler composed of inorganic ceramic powder to produce a composite material. Known thermally conductive fillers include alumina, magnesia, beryllium oxide, boron nitride, aluminum nitride, silicon nitride, silicon carbide, aluminum fluoride, and calcium fluoride. In this technique, a resin composition is filled with a filler for achieving both high thermal conductivity and electrical insulation, so as to achieve both high thermal conductivity and electrical insulation in a composite material. [Prior Art Document] (Patent Document)

Patent Document 1: Japanese Patent No. 4118691 Patent Document 2: Japanese Patent No. 4619770 Patent Document 3: Japanese Patent No. 5471975 Patent Document 4: Japanese Patent Laid-Open No. 2011-84557

[Problem to be Solved by the Invention] The method of increasing the thermal conductivity by increasing the filler filling quantity has an upper limit on the filling amount from the viewpoint of coexistence with electrical insulation, so there is a limit to improving the thermal conductivity of the composite material. On the other hand, from the viewpoint that the thermal conductivity of the composite material can be sharply increased, it is preferable to use a resin with high thermal conductivity. However, resins containing liquid crystalline skeletons generally have a high melting point, so there may be a problem of lowered handling properties.

As a countermeasure against the reduction in handling properties, a method is generally known in which the crystallinity of the resin is lowered to lower the melting point by blending a resin that is compatible with the liquid crystal skeleton-containing resin, thereby improving fluidity. However, the method of blending may hinder the stackability of the cured resin and may not exhibit high thermal conductivity.

The object of the present invention is to provide an epoxy resin composition, a semi-hardened epoxy resin composition and a hardened epoxy resin composition using the epoxy resin composition, which can form an epoxy resin composition with excellent fluidity and high thermal conductivity. Formed products with high glass transition temperature (hereinafter sometimes referred to as Tg). Furthermore, an object of the present invention is to provide a molded product and a molded hardened product having high thermal conductivity and high Tg. [Technical means to solve the problem]

The inventors of the present invention have completed the present invention as a result of intensive research to achieve the above object. In other words, one embodiment of the present invention includes the following aspects.

<1> An epoxy resin composition comprising an epoxy resin and a hardener, wherein the epoxy resin comprises a polymer compound having a structural unit selected from the following general formula (IA) and the following: At least one of the group consisting of structural units represented by the general formula (IB), The aforementioned polymer compound includes a dimer compound, and 1 molecule of the dimer compound contains 2 compounds of the following general formula (II) The structural unit represented, and the proportion of the aforementioned dimer compound in the aforementioned epoxy resin as a whole is 15% by mass to 28% by mass.

In the general formula (IA) and the general formula (IB), R ¹ to R ⁴ each independently represent a hydrogen atom or an alkyl group with 1 to 3 carbons, R ⁵ each independently represent an alkyl group with 1 to 8 carbons, n represents an integer of 0-4.

In the general formula (II), R ¹ to R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbons.

<2> The epoxy resin composition according to <1>, wherein the dimer compound is selected from compounds represented by the following general formula (II-A) and compounds represented by the following general formula (II-B). At least one of the group consisting of compounds and compounds represented by the following general formula (II-C), and the compound represented by the following general formula (II-A), represented by the following general formula (II-B) The ratio of the total amount of the compound and the compound represented by the following general formula (II-C) to the whole said epoxy resin is 15 mass % - 28 mass %.

In general formula (II-A) to general formula (II-C), R ¹ to R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbons, and each R ⁵ independently represents an alkyl group having 1 to 8 carbons The alkyl group, n represents the integer of 0-4.

<3> The epoxy resin composition as described in <1>, wherein the structural unit represented by the general formula (IA) is a structural unit represented by the following general formula (IA') and the structural unit represented by the general formula (IB) The structural unit represented is a structural unit represented by the following general formula (IB').

In general formula (IA') and general formula (IB'), R ¹ to R ⁴ each independently represent a hydrogen atom or an alkyl group with 1 to 3 carbons, and R ⁵ each independently represents an alkyl group with 1 to 8 carbons. base, and n represents an integer of 0-4.

<4> The epoxy resin composition according to <3>, wherein the dimer compound is selected from compounds represented by the following general formula (II-A'), represented by the following general formula (II-B') At least one of the compounds represented by and the group consisting of compounds represented by the following general formula (II-C'), and the compound represented by the following general formula (II-A'), represented by the following general formula (II- The ratio of the total amount of the compound represented by B') and the compound represented by the following general formula (II-C') to the whole epoxy resin is 15 mass % - 28 mass %.

In general formula (II-A') to general formula (II-C'), R ¹ to R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and each R ⁵ independently represents a carbon number 1 ~8 alkyl, n represents an integer of 0-4.

<5> The epoxy resin composition according to any one of <1> to <4>, wherein the epoxy resin contains an epoxy resin monomer represented by the following general formula (I''), and the aforementioned The ratio of an epoxy resin monomer to the said whole epoxy resin is 57 mass % - 80 mass %.

In the general formula (I''), R ¹ to R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

<6> The epoxy resin composition according to any one of <1> to <5>, wherein the hardener includes a novolak resin having a compound selected from the following general formula (II- 1) and a compound of at least one structural unit represented by the group consisting of the following general formula (II-2).

In general formulas (II-1) and (II-2), R ²¹ and R ²⁴ each independently represent an alkyl group, an aryl group or an aralkyl group, and R ²² , R ²³ , R ²⁵ and R ²⁶ each independently represent A hydrogen atom, an alkyl group, an aryl group or an aralkyl group, m21 and m22 each independently represent an integer of 0-2, and n21 and n22 each independently represent an integer of 1-7.

<7> The epoxy resin composition according to any one of <1> to <5>, wherein the hardener includes a novolac resin having a compound selected from the following general formula (III- 1) ~ A compound having at least one structure represented by the group consisting of the following general formula (III-4).

In general formula (III-1) to general formula (III-4), m31 to m34 and n31 to n34 each independently represent a positive integer, Ar ³¹ to Ar ³⁴ each independently represent the following general formula (III-a) Any one of the groups represented by and the groups represented by the following general formula (III-b).

In general formula (III-a) and general formula (III-b), R ³¹ and R ³⁴ each independently represent a hydrogen atom or a hydroxyl group; R ³² and R ³³ each independently represent a hydrogen atom or a carbon number of 1 to 8 alkyl.

<8> The epoxy resin composition according to <6> or <7>, wherein the content of the monomer constituting the novolac resin in the hardener is 10% by mass to 50% by mass, and the monomer is Phenolic compounds.

<9> The epoxy resin composition according to any one of <1> to <8>, which further contains an inorganic filler.

<10> The epoxy resin composition as described in <9>, wherein the material of the aforementioned inorganic filler contains at least one selected from the group consisting of alumina, boron nitride, aluminum nitride, silicon oxide, and magnesium oxide. A sort of.

<11> The epoxy resin composition according to <9> or <10>, wherein the content of the inorganic filler is 60% by volume to 90% by volume in the solid content.

<12> The epoxy resin composition according to any one of <1> to <11>, which further contains a silane coupling agent.

<13> The epoxy resin composition according to <12>, wherein the silane coupling agent includes a silane coupling agent having a phenyl group.

<14> A semi-cured epoxy resin composition which is a semi-cured body of the epoxy resin composition described in any one of <1> to <13>.

<15> A cured epoxy resin composition which is a cured body of the epoxy resin composition described in any one of <1> to <13>.

<16> A molded article produced by press-molding the epoxy resin composition described in any one of <1> to <13>.

<17> A molded hardened product obtained by post-hardening the molded product described in <16> by heating. [effect]

According to the present invention, it is possible to provide an epoxy resin composition, a semi-hardened epoxy resin composition and a hardened epoxy resin composition using the epoxy resin composition, which can form a liquid crystal having excellent fluidity and high thermal conductivity. properties and high Tg moldings. Furthermore, according to the present invention, it is possible to provide a molded product and a molded hardened product having high thermal conductivity and high Tg.

Embodiments of the present invention will be described in detail below. However, the present invention is not limited to the following embodiments. In the following embodiments, the constituent elements (including element steps, etc.) are not essential unless otherwise specified. Numerical values and their ranges are also the same, and are not intended to limit the present invention. In this specification, the term "step" includes steps that are independent from other steps, even if they cannot be clearly distinguished from other steps, as long as the purpose of the step can be achieved. In addition, in this specification, in the numerical range represented by "~", the numerical values described before and after "~" are included as the minimum value and the maximum value, respectively. In the numerical ranges described step by step in this specification, the upper limit or lower limit described in one numerical range may be replaced by the upper limit or lower limit of the numerical range described in other steps. In addition, in the numerical range described in this specification, the upper limit or the lower limit of the numerical range may be replaced with the value disclosed in the Example. In this specification, the content rate or content of each component in the composition means the percentage of the plurality of substances present in the composition, unless otherwise specified, when there are multiple substances corresponding to each component in the composition. Total content or content. In this specification, the particle size of each component in the composition means that when there are plural types of particles corresponding to each component in the composition, unless otherwise specified, it means the mixture of the plural types of particles present in the composition. value.

<Epoxy Resin Composition> The epoxy resin composition of the present invention contains an epoxy resin and a hardener. The epoxy resin contains a polymer compound having a compound selected from the group represented by the following general formula (IA): Structural unit and at least one of the group consisting of structural units represented by the following general formula (IB), the aforementioned polymer compound includes a dimer compound, and one molecule of the dimer compound contains two compounds represented by the following general formula: The structural unit represented by formula (II), and the proportion of the dimer compound in the entire epoxy resin is 15% by mass to 28% by mass.

In the general formula (IA) and the general formula (IB), R ¹ to R ⁴ each independently represent a hydrogen atom or an alkyl group with 1 to 3 carbons, R ⁵ each independently represent an alkyl group with 1 to 8 carbons, n represents an integer of 0-4.

In the general formula (II), R ¹ to R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbons.

The epoxy resin composition of the present invention is excellent in fluidity. In addition, molded products and molded cured products using the epoxy resin composition of the present invention can have high thermal conductivity and high Tg. Each component contained in the epoxy resin composition of the present invention is described in detail below.

- Epoxy resin - The epoxy resin used in the present invention is set as follows: comprising a polymer compound having a structural unit selected from the general formula (IA) and the general formula (IB ) at least one of the group consisting of structural units represented by the polymer compound includes a dimer compound, the dimer compound contains two structural units represented by general formula (II) in one molecule, and the two The ratio of the polymer compound to the whole epoxy resin is 15% by mass to 28% by mass. Furthermore, the term "polymer compound" in the present invention refers to a compound containing two or more structural units represented by the general formula (II) in one molecule.

In general formula (IA) and general formula (IB), R ¹ to R ⁴ each independently represent a hydrogen atom or an alkyl group with 1 to 3 carbons, preferably a hydrogen atom or an alkyl group with 1 to 2 carbons, A hydrogen atom or a methyl group is preferred, and a hydrogen atom is more preferred. Furthermore, preferably two to four of R ¹ to R ⁴ are hydrogen atoms, more preferably three or four are hydrogen atoms, and even more preferably all four are hydrogen atoms. When any one of R ¹ to R ⁴ is an alkyl group having 1 to 3 carbons, preferably at least one of R ¹ and R ⁴ is an alkyl group having 1 to 3 carbons. Furthermore, in general formula (II), specific examples of R ¹ to R ⁴ are the same as those of general formula (IA) and general formula (IB), and their preferred ranges are also the same.

In general formula (IA) and general formula (IB), R ⁵ each independently represents an alkyl group having 1 to 8 carbon atoms, preferably an alkyl group having 1 to 3 carbon atoms, and more preferably a methyl group. In general formula (IA) and general formula (IB), n represents an integer of 0-4, preferably an integer of 0-2, preferably an integer of 0-1, more preferably 0. In other words, in general formula (IA) and general formula (IB), the benzene ring marked with ^R preferably has two to four hydrogen atoms, more preferably has three or four hydrogen atoms, and even more preferably has four hydrogen atoms.

The number of the structural units represented by the general formula (II) contained in the polymer compound is arbitrary and not particularly limited, and the average value is preferably 5 or less, preferably 3 or less.

In the present invention, preferably the structural unit represented by the general formula (IA) is selected from the group consisting of the structural unit represented by the following general formula (IA') and the structural unit represented by the following general formula (IA'') At least one structural unit represented by the general formula (IB) in the group is selected from the group consisting of a structural unit represented by the following general formula (IB') and a structural unit represented by the following general formula (IB'') At least one of them, preferably the structural unit represented by the general formula (IA) is a structural unit represented by the following general formula (IA') and the structural unit represented by the general formula (IB) is represented by the following general formula (IB' ) represents the structural unit.

In general formula (IA'), general formula (IB'), general formula (IA'') and general formula (IB''), specific examples of R ¹ to R ⁵ and n are the same as general formula (IA) and general formula Formula (IB) is the same, and its preferred range is also the same.

The epoxy resin used in the present invention contains a dimer compound containing two structural units represented by the following general formula (II) in 1 molecule. Specific examples of dimer compounds containing two structural units represented by the following general formula (II) in one molecule include: compounds represented by the following general formula (II-A), represented by the following general formula At least one selected from the group consisting of a compound represented by (II-B) and a compound represented by the following general formula (II-C).

In general formula (II-A), general formula (II-B) and general formula (II-C), specific examples of R ¹ to R ⁵ and n are the same as those of general formula (IA) and general formula (IB), The preferred range is also the same.

When at least one selected from the group consisting of the structural unit represented by the general formula (IA') and the structural unit represented by the general formula (IB') is included, as a specific example of the dimer compound, for example, : selected from the group consisting of compounds represented by the following general formula (II-A'), compounds represented by the following general formula (II-B') and compounds represented by the following general formula (II-C') at least one of .

In general formula (II-A'), general formula (II-B') and general formula (II-C'), specific examples of R ¹ to R ⁵ and n are the same as general formula (IA) and general formula (IB ) are the same, and their preferred ranges are also the same.

In addition, when at least one selected from the group consisting of the structural unit represented by the general formula (IA'') and the structural unit represented by the general formula (IB'') is included, as a specific example of the dimer compound , for example: selected from compounds represented by the following general formula (II-A''), compounds represented by the following general formula (II-B'') and compounds represented by the following general formula (II-C'') At least one of the group consisting of compounds.

In the general formula (II-A''), the general formula (II-B'') and the following general formula (II-C''), the specific examples of R ¹ to R ⁵ and n are the same as the general formula (IA) It is the same as general formula (IB), and its preferable range is also the same.

In the present invention, as a specific example of the dimer compound, it is preferably selected from compounds represented by the general formula (II-A'), compounds represented by the general formula (II-B') and compounds represented by the general formula (II- At least one of the group consisting of compounds represented by C').

The structure of these dimer compounds can be determined by comparing the following molecular weights: the molecular weight of the structure is presumed to be the epoxy compound represented by the general formula (I'') used in the synthesis of epoxy resins. Resin monomer reacts with a benzene ring having two hydroxyl groups as a substituent of a divalent phenolic compound; the molecular weight of the target compound is determined by liquid chromatography, which It is performed using a liquid chromatograph with ultraviolet (UV) spectroscopy and mass detectors. Liquid chromatography was performed using LaChrom II C18 manufactured by Hitachi, Ltd. as an analytical column, tetrahydrofuran as an eluent, and a flow rate of 1.0 mL/min. The UV spectral detector detects the absorbance at a wavelength of 280 nm. In addition, the mass spectrometer is detected by setting the ionization voltage to 2700 V. Furthermore, the details of the synthesis method and evaluation of epoxy resin are described later.

In the present invention, the ratio of the dimer compound to the entire epoxy resin is 15% by mass to 28% by mass. This ratio can be calculated|required by the reverse chromatography (Reversed Phase Liquid Chromatography, RPLC) measurement mentioned later.

When the proportion of the dimer compound is less than 15% by mass, the melt viscosity of the epoxy resin does not decrease, and molding becomes difficult, so a molded product cannot be produced or the density of the molded product tends to decrease. Moreover, when the ratio of a dimer compound exceeds 28 mass %, the crosslink density of a molded product will fall, and as a result, the thermal conductivity and Tg of a molded product will tend to fall. The proportion of the dimer compound is preferably 20% by mass to 27% by mass, more preferably 22% by mass to 25% by mass.

In addition, the epoxy resin may contain an epoxy resin monomer represented by the following general formula (I'').

In the general formula (I''), R ¹ to R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Furthermore, in general formula (I''), specific examples of R ¹ to R ⁴ are the same as those of general formula (IA) and general formula (IB), and their preferred ranges are also the same.

The proportion of the epoxy resin monomer represented by the general formula (I'') in the entire epoxy resin is preferably 57% by mass to 80% by mass. If the ratio of the epoxy resin monomer is 57% by mass or more, in other words, it means that the reaction product of the epoxy resin monomer represented by the general formula (I'') and the dihydric phenolic compound will not be too much, Therefore, the crosslinking density of the molded product is not easily lowered, and as a result, the thermal conductivity and Tg of the molded product tend to be less likely to be lowered. On the other hand, if the ratio of the epoxy resin monomer is 80% by mass or less, in other words, it means the reaction product of the epoxy resin monomer represented by the general formula (I'') and the dihydric phenolic compound If the amount is not too small, the molded product tends to be difficult to form easily, or the crosslink density of the molded product tends not to decrease easily.

The proportion of the epoxy resin monomer represented by the general formula (I'') in the entire epoxy resin is preferably 59% by mass to 74% by mass, more preferably 62% by mass to 70% by mass.

The epoxy resin used in the present invention may contain other epoxy resin components in addition to the polymer compound and the epoxy resin monomer represented by the general formula (I''). The proportion of other epoxy resin components in the whole epoxy resin is preferably less than 15% by mass, more preferably at most 10% by mass, more preferably at most 8% by mass, and particularly preferably not substantially containing other epoxy resins. Resin composition.

In this description, the RPLC measurement uses Mightysil RP-18 manufactured by Kanto Chemical Co., Ltd. as an analytical RPLC column, and uses a gradient method to make the mixing ratio (volume basis) of the eluent from acetonitrile/tetrahydrofuran/water=20 /5/75 was carried out by changing continuously to acetonitrile/tetrahydrofuran=50/50 (35 minutes from the start) via acetonitrile/tetrahydrofuran=80/20 (20 minutes from the start). Also, set the flow rate to 1.0 mL/min. In this specification, the absorbance at a wavelength of 280 nm is detected, and the total area of all detected peaks is set to 100, and the ratio of the areas of corresponding peaks is obtained, and the value is set as the value of each compound at Content rate [mass %] in the whole epoxy resin.

In addition, the epoxy group equivalent weight of an epoxy resin is measured by the perchloric acid titration method. From the point of view of co-existing the fluidity of the epoxy resin composition and the thermal conductivity of the molded product, the epoxy group equivalent is preferably 245 g/eq to 300 g/eq, and 250 g/eq to 290 g/eq is better. Good, preferably 260 g/eq ~ 280 g/eq. If the epoxy group equivalent of the epoxy resin is 245 g/eq or more, the crystallinity of the epoxy resin will not be too high, so the fluidity of the epoxy resin composition tends to be less likely to decrease. On the other hand, when the epoxy group equivalent of the epoxy resin is 300 g/eq or less, the crosslinking density of the epoxy resin is less likely to decrease, so the thermal conductivity of the molded product tends to increase.

In addition, from the viewpoint of coexistence of the fluidity of the epoxy resin composition and the thermal conductivity of the molded product, the number average molecular weight (Mn) of the epoxy resin when measured by gel permeation chromatography (GPC) is 400 to 800 Preferably, 450-750 is more preferable, and 500-700 is more preferable. If the Mn of the epoxy resin is 400 or more, the crystallinity of the epoxy resin will not be too high, so the fluidity of the epoxy resin composition tends to be less likely to decrease. When the Mn of the epoxy resin is 800 or less, the crosslinking density of the epoxy resin is less likely to decrease, so the thermal conductivity of the molded product tends to increase.

In this specification, the GPC measurement uses G2000HXL and 3000HXL manufactured by Tosoh Co., Ltd. as the GPC column for analysis, and tetrahydrofuran is used as the mobile phase, the sample concentration is set to 0.2% by mass, and the flow rate is set to 1.0 mL/ min to measure. A calibration curve was created using a polystyrene standard sample, and Mn was calculated as a polystyrene conversion value.

Epoxy resins containing polymer compounds can be synthesized by making an epoxy resin monomer represented by the general formula (I''), a divalent phenolic compound having two hydroxyl groups as substituents on one benzene ring And the hardening catalyst mentioned later was dissolved in the synthetic solvent, and it stirred while heating. Although it is also possible to synthesize|combine by the method of making an epoxy resin monomer melt and react without using a solvent, it may be necessary to raise temperature to the temperature at which an epoxy resin monomer melts. Therefore, from the viewpoint of safety, a synthesis method using a synthesis solvent is preferable.

As the synthesis solvent, it can be heated to the temperature required for reacting the epoxy resin monomer represented by the general formula (I'') with a divalent phenolic compound having two hydroxyl groups as substituents on one benzene ring. The solvent is not particularly limited. As specific examples, for example: cyclohexanone, cyclopentanone, ethyl lactate, propylene glycol monomethyl ether, N-methylpyrrolidone, etc.

The amount of the synthesis solvent is set to exceed the amount of the epoxy resin monomer represented by the general formula (I''), a benzene ring having two hydroxyl groups as substituents, and a hardening catalyst. amount of dissolved. Although the solubility varies depending on the type of raw material before the reaction, the type of solvent, etc., if the concentration of the fed solid content is 20% to 60% by mass, the viscosity of the resin solution after synthesis will become better. range of tendencies.

Examples of the bivalent phenol compound having two hydroxyl groups as substituents on one benzene ring include catechol, resorcinol, hydroquinone, and derivatives thereof. Examples of derivatives include compounds in which a benzene ring is substituted with an alkyl group having 1 to 8 carbon atoms. Among these divalent phenolic compounds, it is preferable to use resorcinol and hydroquinone, and it is more preferable to use hydroquinone from the viewpoint of improving the thermal conductivity of the molded article. We think that the polymer compound obtained by reacting hydroquinone with the epoxy resin monomer tends to have a linear structure because the structure of hydroquinone is substituted with two hydroxyl groups in a para positional relationship. Therefore, the stackability of molecules is high and it is easy to form a high-order structure. One of these divalent phenolic compounds can be used alone, or two or more can be used in combination.

The type of the above-mentioned curing catalyst is not particularly limited, and an appropriate curing catalyst can be selected from the viewpoints of reaction speed, reaction temperature, storage stability, and the like. Specific examples of the curing catalyst include imidazole compounds, organophosphorus compounds, tertiary amines, quaternary ammonium salts, and the like. These may be used individually by 1 type, and may use 2 or more types together. Among them, at least one selected from the group consisting of organic phosphine compounds, maleic anhydride, quinone compounds (1,4-benzoquinone, 2 ,5-Methylbenzoquinone, 1,4-Naphthoquinone, 2,3-Dimethylbenzoquinone, 2,6-Dimethylbenzoquinone, 2,3-Dimethoxy-5-methyl-1,4 -Benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, phenyl-1,4-benzoquinone, etc.), diazophenylmethane, phenol resin and other compounds with π bonds are added to the organic Compounds with intramolecular polarization made of phosphine compounds; and complexes of organophosphine compounds and organoboron compounds (tetraphenyl borate, tetra(p-toluene) borate, tetra(n-butyl) borate, etc.).

Specific examples of organic phosphine compounds include: triphenylphosphine, diphenyl (p-tolyl) phosphine, ginseng (alkylphenyl) phosphine, ginseng (alkoxyphenyl) phosphine, ginseng (alkyl alkane) Oxyphenyl) phosphine, ginseng (dialkylphenyl) phosphine, ginseng (trialkylphenyl) phosphine, ginseng (tetraalkylphenyl) phosphine, ginseng (dialkoxyphenyl) phosphine, ginseng ( Trialkoxyphenyl)phosphine, para(tetraalkoxyphenyl)phosphine, trialkylphosphine, dialkylarylphosphine, alkyldiarylphosphine, and the like.

The amount of the hardening catalyst is not particularly limited. From the viewpoint of reaction speed and storage stability, the total mass of divalent phenolic compounds having two hydroxyl groups as substituents in the epoxy resin monomer represented by the general formula (I'') and one benzene ring , preferably 0.1% by mass to 1.5% by mass, more preferably 0.2% by mass to 1% by mass.

The epoxy resin containing a polymer compound can be synthesized using a glass flask on a small scale, and can be synthesized using a stainless steel synthesis pot on a large scale. A specific synthesis method is, for example, as described below. First, put the epoxy resin monomer represented by the general formula (I'') into a flask or a synthesis pot, and after adding a synthesis solvent, heat it up to the reaction temperature by an oil bath or heat medium to make the epoxy resin Monomer dissolved. A divalent phenolic compound having two hydroxyl groups as substituents on a benzene ring is put into it, and after confirming that it dissolves in a synthesis solvent, a hardening catalyst is put in to start the reaction. An epoxy resin solution containing a polymer compound can be obtained as long as the reaction solution is taken out after a predetermined time. In addition, in a flask or a synthesis pot, as long as the synthesis solvent is distilled off under reduced pressure under heating conditions and then taken out, epoxy resin containing a polymer compound can be obtained as a solid at room temperature (25°C). resin.

The reaction temperature is not limited as long as it is the temperature at which the epoxy group and the phenolic hydroxyl group will react in the presence of a hardening catalyst. better within range. There exists a tendency for the time until reaction completion|finish to be shortened further by making reaction temperature 100 degreeC or more. On the other hand, the possibility of gelation tends to be reduced by setting the reaction temperature to 180° C. or lower.

When synthesizing an epoxy resin containing a polymer compound, the equivalent of the epoxy resin monomer represented by the general formula (I'') and the dihydric phenolic compound having two hydroxyl groups as substituents on one benzene ring can be changed Compared to synthesis. Specifically, it can be synthesized in the following manner: the equivalent number (Ep) of the epoxy group of the epoxy resin monomer represented by the general formula (I'') and 2 benzene rings having two hydroxyl groups as substituents The ratio (Ep/Ph) of the number of equivalents (Ph) of the phenolic hydroxyl group of the polyphenolic compound is in the range of 100/100 to 100/1. From the viewpoint of the fluidity of the epoxy resin composition and the heat resistance and thermal conductivity of the molded product, Ep/Ph is preferably in the range of 100/18 to 100/10. When Ep/Ph is set to be 100/10 or less, it is possible to suppress a decrease in the density of crosslinking points and to improve the heat resistance and thermal conductivity of the molded article. On the other hand, setting Ep/Ph to be 100/18 or more lowers the softening point of the obtained polymer compound and improves the fluidity of the epoxy resin composition.

In addition, the polymer compound and the epoxy resin monomer represented by the general formula (I'') have a liquid crystal group in the molecular structure. Patent Document 1 describes the fact that a cured body of an epoxy resin having a liquid crystalline group in its molecular structure is excellent in thermal conductivity. In addition, it is described in WO2013/065159 that combining a novolac resin obtained by novolakizing a divalent phenolic compound and an epoxy resin monomer represented by the general formula (I'') can realize relatively High thermal conductivity and high Tg.

Here, the liquid crystal group refers to a functional group that tends to exhibit crystallinity or liquid crystallinity due to the effect of intermolecular interaction. Specifically, representative examples include biphenyl, phenylbenzoic acid, azophenyl, distyryl, derivatives thereof, and the like.

Furthermore, it is stated in WO2013/065159 that the epoxy resin monomer represented by the general formula (I'') forms a higher-order structure with higher order by centering on inorganic fillers, especially alumina fillers , and the thermal conductivity of the hardened body will increase sharply. This fact is also consistent with epoxy resins comprising polymeric compounds. We believe that the reason should be: the presence of inorganic fillers makes the hardened body of the epoxy resin monomer that has formed a high-order structure an efficient heat conduction channel, and can obtain high thermal conductivity.

Here, the high-order structure refers to a structure including a high-order structure whose constituent elements are arranged to form a fine ordered structure, and for example, a crystal phase and a liquid crystal phase correspond to this structure. Whether or not such a higher-order structure exists can be easily judged by observing with a polarizing microscope. In other words, it can be judged by observing the interference fringes caused by the disappearance of the polarized light when observed under the crossed nicol state. This high-order structure usually exists in the form of islands in the hardened epoxy resin composition and forms a domain structure, and one island corresponds to one high-order structure. The constituent elements of this higher-order structure are generally formed by covalent bonds.

In addition, formation of a higher-order structure in a cured epoxy resin composition containing an inorganic filler can be confirmed as follows. Prepare the cured body of the composition (thickness: 0.1-20 μm), the cured body of the composition is to add 5 vol% to 10 vol% of inorganic fillers such as alumina filler to the mixture of epoxy resin, hardener and hardening catalyst And get. The obtained cured body was observed using a polarizing microscope (for example, BX51 manufactured by Olympus Co., Ltd.) in a state sandwiched between glass slides (thickness: about 1 mm). An interference pattern centered on the inorganic filler can be observed in a region where the inorganic filler exists, but no interference pattern can be observed in a region where the inorganic filler does not exist. From this, it can be seen that the cured epoxy resin has a high-order structure centered on the inorganic filler.

Furthermore, observation is not performed in a crossed polarization state, but needs to be performed in a state where the analyzer is rotated by 60° relative to the polarizer. When observed under the crossed polarization state, the region where the interference pattern cannot be observed (that is, the region where the cured resin does not form a higher-order structure) becomes a dark field, and cannot be distinguished from the inorganic filler portion. However, when the analyzer is rotated by 60° with respect to the polarizer, the region where the interference pattern cannot be observed does not become a dark field, but can be distinguished from the inorganic filler portion.

However, epoxy resin monomers having a liquid crystalline group in their molecular structure are generally easy to crystallize, and tend to have a higher melting temperature than epoxy resin monomers that are generally used. Furthermore, the epoxy resin monomer represented by the general formula (I'') is also equivalent to the epoxy resin monomer having a liquid crystal group in the molecular structure. However, by polymerizing a part of such an epoxy resin monomer to produce a polymer compound, crystallization can be suppressed and the melting temperature can be lowered. As a result, the moldability of the epoxy resin composition is improved. Specifically, as mentioned above, the epoxy resin monomer represented by the general formula (I'') reacts with a dihydric phenolic compound having two hydroxyl groups as substituents on a benzene ring to produce a polymer compound, that is, the above-mentioned effects are easily obtained.

-Curing Agent- The epoxy resin composition of the present invention contains a curing agent. The type of curing agent is not particularly limited, and conventionally known curing agents can be used. In the present invention, a novolak resin obtained by novolakizing a divalent phenolic compound (hereinafter sometimes referred to as "specific novolak resin") is preferable.

Examples of the divalent phenolic compound include catechol, resorcinol, hydroquinone, 1,2-naphthalenediol, 1,3-naphthalenediol, and the like. The novolak resin obtained by novolakizing a divalent phenolic compound means a novolac resin in which these divalent phenolic compounds are linked by a methylene chain. The use of divalent phenolic compounds can improve the thermal conductivity of the molded product, and the novolakization of these compounds can further improve the heat resistance of the molded product.

The specific novolak resin preferably contains a compound having a structural unit represented by at least one selected from the group consisting of the following general formula (II-1) and the following general formula (II-2).

In the general formulas (II-1) and (II-2), R ²¹ and R ²⁴ each independently represent an alkyl group, an aryl group or an aralkyl group. The alkyl group, aryl group, and aralkyl group represented by R ²¹ or R ²⁴ may have a substituent. As a substituent of an alkyl group, an aryl group, a hydroxyl group, a halogen atom, etc. are mentioned, for example. As a substituent of an aryl group and an aralkyl group, an alkyl group, an aryl group, a hydroxyl group, a halogen atom, etc. are mentioned, for example.

R ²¹ and R ²⁴ each independently represent an alkyl group, an aryl group or an aralkyl group, preferably an alkyl group with 1 to 6 carbons, an aryl group with 6 to 12 carbons, or an aralkyl group with 7 to 13 carbons , preferably an alkyl group with 1 to 6 carbon atoms.

m21 and m22 each independently represent the integer of 0-2. When m21 is 2, the two ^R21s may be the same or different, and when m22 is 2, the two ^R24s may be the same or different. In the present invention, m21 and m22 are independently preferably 0 or 1, more preferably 0. In addition, n21 and n22 each independently represent an integer of 1 to 7, and each represents a contained number of a structural unit represented by general formula (II-1) or a structural unit represented by general formula (II-2).

In the general formulas (II-1) and (II-2), R ²² , R ²³ , R ²⁵ and R ²⁶ each independently represent a hydrogen atom, an alkyl group, an aryl group or an aralkyl group. The alkyl group, aryl group and aralkyl group represented by R ²² , R ²³ , R ²⁵ and R ²⁶ may have a substituent. As a substituent of an alkyl group, an aryl group, a hydroxyl group, a halogen atom, etc. are mentioned, for example. As a substituent of an aryl group and an aralkyl group, an alkyl group, an aryl group, a hydroxyl group, a halogen atom, etc. are mentioned, for example.

From the standpoint of the storage stability of the epoxy resin composition and the thermal conductivity of the molded product, R ²² , R ²³ , R ²⁵ and R ²⁶ are preferably hydrogen atoms, alkyl groups or aryl groups, and hydrogen atoms, carbon number An alkyl group with 1-4 carbon atoms or an aryl group with 6-12 carbon atoms is preferred, and a hydrogen atom is more preferred. And, from the viewpoint of the heat resistance of the molding, at least one of ^R22 and ^R23 , or at least one of ^R25 and ^R26 is also preferably an aryl group, and an aryl group with 6 to 12 carbons is preferred. good. In addition, the said aryl group may contain a heteroatom in an aromatic group, Preferably it is a heteroaryl group whose total number of a heteroatom and carbon is 6-12.

The specific novolac resin may contain a single compound having a structural unit represented by general formula (II-1) or a structural unit represented by general formula (II-2), or may contain a compound having a structural unit represented by general formula (II-1) Two or more compounds of the structural unit represented by the general formula (II-2) or the structural unit represented by the general formula (II-2). From the viewpoint of the thermal conductivity of the molded article, the curing agent preferably contains at least a compound having a structural unit represented by the general formula (II-1), more preferably at least a compound having a structural unit represented by the general formula (II-1) and A compound derived from a structural unit of resorcinol.

When the compound having the structural unit represented by the general formula (II-1) has a resorcinol-derived structural unit, it may further contain at least one of partial structures derived from a phenolic compound other than resorcinol. Examples of phenolic compounds other than resorcinol in compounds having a structural unit represented by general formula (II-1) include phenol, cresol, catechol, hydroquinone, 1,2,3- Trihydroxybenzene, 1,2,4-trihydroxybenzene, 1,3,5-trihydroxybenzene, etc. The compound having the structural unit represented by the general formula (II-1) may contain one kind of partial structures derived from these phenolic compounds alone, or may contain two or more kinds of partial structures derived from these phenolic compounds in combination. . In addition, the catechol-derived structural unit represented by the general formula (II-2) may contain at least one of partial structures derived from phenolic compounds other than catechol.

Here, the partial structure derived from a phenolic compound means a monovalent group or a divalent group formed by removing one or two hydrogen atoms from an aromatic ring portion of a phenolic compound. In addition, the position from which a hydrogen atom is removed is not specifically limited.

Among the compounds having a structural unit represented by the general formula (II-1), phenols other than resorcinol are derived from the viewpoints of thermal conductivity of moldings, adhesiveness and storage stability of epoxy resin compositions. The partial structure of the compound is preferably derived from the group consisting of phenol, cresol, catechol, hydroquinone, 1,2,3-trihydroxybenzene, 1,2,4-trihydroxybenzene and 1,3,5 - The partial structure of at least one selected from the group consisting of trihydroxybenzene, more preferably derived from the partial structure of at least one selected from the group consisting of catechol and hydroquinone.

Furthermore, when the compound having the structural unit represented by the general formula (II-1) contains a resorcinol-derived structural unit, the content ratio of the resorcinol-derived partial structure is not particularly limited. Relative to the total mass of the compound having a structural unit represented by general formula (II-1), the content ratio of the partial structure derived from resorcinol is preferably 55% by mass or more from the viewpoint of elastic modulus, From the viewpoint of the Tg and linear expansion coefficient of the molded product, it is preferably at least 60 mass%, more preferably at least 80 mass%, and particularly preferably at least 90 mass% from the viewpoint of the thermal conductivity of the molded product.

Furthermore, it is also preferable that the specific novolak resin contains a compound having a structure represented by at least one selected from the group consisting of the following general formulas (III-1) to (III-4).

In general formula (III-1) to general formula (III-4), m31 to m34 and n31 to n34 each independently represent a positive integer, Ar ³¹ to Ar ³⁴ each independently represent the following general formula (III-a) Any one of the groups represented by and the groups represented by the following general formula (III-b).

In general formula (III-a) and general formula (III-b), R ³¹ and R ³⁴ each independently represent a hydrogen atom or a hydroxyl group; R ³² and R ³³ each independently represent a hydrogen atom or a carbon number of 1 to 8 alkyl.

A specific novolak resin having a structure represented by at least one selected from the group consisting of general formula (III-1) to general formula (III-4) can be converted to novolac by dihydric phenolic compounds By-products are produced by the manufacturing method described later.

The structure represented by at least one selected from the group consisting of general formula (III-1) to general formula (III-4) may contain it as the main chain skeleton of the specific novolac resin, and may also contain its as part of the side chains of certain novolac resins. In addition, each structural unit constituting the structure represented by any one of general formula (III-1) to general formula (III-4) may be contained randomly, or may be contained regularly, and may also be block Contains like. In addition, in the general formula (III-1) to general formula (III-4), the substitution position of the hydroxyl group is not particularly limited as long as it is on the aromatic ring.

In each of the general formulas (III-1) to (III-4), the plurality of Ar ³¹ to Ar ³⁴ may all be the same atomic group, and may contain two or more kinds of atomic groups. In addition, Ar ³¹ to Ar ³⁴ each independently represent any one of the group represented by the general formula (III-a) and the group represented by the general formula (III-b).

In general formula (III-a) and general formula (III-b), R ³¹ and R ³⁴ each independently represent a hydrogen atom or a hydroxyl group, and a hydroxyl group is preferable from the viewpoint of thermal conductivity of the molded product. In addition, the substitution positions of R ³¹ and R ³⁴ are not particularly limited.

In addition, in the general formula (III-a), R ³² and R ³³ each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. In R ³² and R ³³ , as the alkyl group with 1 to 8 carbons, for example: methyl, ethyl, propyl, butyl, isopropyl, isobutyl, tertiary butyl, pentyl, hexyl , heptyl, octyl, etc. In addition, in the general formula (III-a), the substitution positions of R ³² and R ³³ are not particularly limited.

From the viewpoint of achieving excellent thermal conductivity of the molded product, in general formula (III-1) to general formula (III-4), Ar ³¹ to Ar ³⁴ are preferably each independently selected from dihydroxybenzene-derived group (that is, in the general formula (III-a), R ³¹ is a hydroxyl group and R ³² and R ³³ are hydrogen atoms) and a group derived from dihydroxynaphthalene (that is, in the general formula (III-b), ^R34 is at least one of the group consisting of hydroxyl group).

Here, the "group derived from dihydroxybenzene" means a divalent group formed by removing two hydrogen atoms from the aromatic ring portion of dihydroxybenzene, and the position where the hydrogen atoms are removed is not particularly limited. In addition, the "group derived from dihydroxynaphthalene" etc. have the same meaning.

In addition, from the viewpoint of productivity and fluidity of the epoxy resin composition, each of Ar ³¹ to Ar ³⁴ is preferably a group derived from dihydroxybenzene, preferably a group derived from 1,2-dihydroxybenzene. At least one selected from the group consisting of a group derived from hydroxybenzene (catechol) and a group derived from 1,3-dihydroxybenzene (resorcinol). Ar ³¹ to Ar ³⁴ preferably contain at least a resorcinol-derived group from the viewpoint of particularly improving the thermal conductivity of the molded article. In addition, from the viewpoint of particularly improving the thermal conductivity of the molded article, it is preferable to contain structural units represented by numbers n31 to n34, preferably at least a partial structure derived from resorcinol.

When the specific novolak resin comprises a partial structure derived from resorcinol, in the total mass of compounds having at least one structure shown in general formula (III-1) to general formula (III-4), the source The content of the partial structure derived from resorcinol is preferably at least 55% by mass, more preferably at least 60% by mass, more preferably at least 80% by mass, and particularly preferably at least 90% by mass.

In general formula (III-1) to general formula (III-4), from the viewpoint of fluidity of the epoxy resin composition, m31～m34 and n31～n34 are m/n=1/5～20/ 1 is preferable, m/n=5/1-20/1 is more preferable, m/n=10/1-20/1 is more preferable. Further, from the viewpoint of the fluidity of the epoxy resin composition, (m+n) is preferably 20 or less, more preferably 15 or less, and more preferably 10 or less. In addition, the lower limit value of (m+n) is not specifically limited. Here, m is m31 when n is n31, m is m32 when n is n32, m is m33 when n is n33, and m is m34 when n is n34.

A novolac resin having a structure represented by at least one selected from the group consisting of general formula (III-1) to general formula (III-4), especially when its Ar ³¹ to Ar ³⁴ are derived from When at least one of a group derived from a substituted or unsubstituted dihydroxybenzene group and a group derived from a substituted or unsubstituted dihydroxynaphthalene, a novolac resin obtained by simply novolakizing these, etc. In comparison, it tends to be easier to synthesize and obtain a novolac resin with a lower softening point. Therefore, there is an advantage that a resin composition containing such a novolac resin as a curing agent is also easy to manufacture and handle. Furthermore, whether the novolac resin has a partial structure shown in at least one of the general formula (III-1) ~ general formula (III-4), can be determined by electric field desorption ionization mass spectrometry (FD-MS), It is judged by whether or not a component corresponding to the partial structure represented by at least one of the general formulas (III-1) to (III-4) is included as the fragment component.

The molecular weight of the specific novolac resin is not particularly limited. From the viewpoint of fluidity of the epoxy resin composition, the number average molecular weight (Mn) is preferably not more than 2000, more preferably not more than 1500, more preferably not less than 350 and not more than 1500. In addition, the weight average molecular weight (Mw) is preferably not more than 2000, more preferably not more than 1500, more preferably not less than 400 and not more than 1500. These Mn and Mw are measured by a general method using GPC.

The hydroxyl equivalent of the specific novolak resin is not particularly limited. From the viewpoint of the crosslink density related to the heat resistance of the molded product, the average value of the hydroxyl equivalent is preferably 50 g/eq to 150 g/eq, and the average value is more preferably 50 g/eq to 120 g/eq , with an average value of 55 g/eq to 120 g/eq is better.

The hardener may contain a monomer constituting a specific novolak resin, which is a phenolic compound. The content ratio of the monomers (phenolic compounds) constituting the specific novolak resin (hereinafter also referred to as "monomer content ratio") is not particularly limited. From the viewpoint of the thermal conductivity and heat resistance of the molded product and the formability of the epoxy resin composition, the content of the monomer is preferably 10% by mass to 50% by mass, more preferably 15% by mass to 45% by mass, and at least 20% by mass to 40% by mass is more preferable.

When the monomer content ratio is less than 50% by mass, the monomer that does not contribute to crosslinking during the hardening reaction will be reduced and the high molecular weight body that will be crosslinked will be increased, so a higher-density higher-order structure will be formed to improve molding. The tendency of the material to conduct heat. In addition, when the monomer content ratio is 10% by mass or more, it tends to flow easily during molding, so that the adhesion with the filler is further improved, and more excellent thermal conductivity and heat resistance of the molded product tend to be achieved.

In the epoxy resin composition, the content of the curing agent is not particularly limited. Preferably, the ratio of the active hydrogen equivalent of the phenolic hydroxyl group in the curing agent (phenolic hydroxyl equivalent) to the equivalent weight of the epoxy group of the epoxy resin (phenolic hydroxyl equivalent/epoxy group equivalent) is 0.5 to 2, more preferably It is better to be 0.8 to 1.2.

In addition, the epoxy resin composition may further include a curing catalyst as needed. The inclusion of a curing catalyst enables the epoxy resin composition to be more fully cured. The type and content of the curing catalyst are not particularly limited, and an appropriate type and content can be selected from the viewpoints of reaction speed, reaction temperature, storage properties, and the like. Specific examples include imidazole compounds, organophosphorus compounds, tertiary amines, quaternary ammonium salts, and the like. These may be used alone or in combination of two or more. Among them, at least one selected from the group consisting of organophosphine compounds and complexes of organophosphine compounds and organoboron compounds is preferred from the viewpoint of heat resistance of molded articles.

Specific examples of organic phosphine compounds include: triphenylphosphine, diphenyl (p-tolyl) phosphine, ginseng (alkylphenyl) phosphine, ginseng (alkoxyphenyl) phosphine, ginseng (alkyl alkane) Oxyphenyl) phosphine, ginseng (dialkylphenyl) phosphine, ginseng (trialkylphenyl) phosphine, ginseng (tetraalkylphenyl) phosphine, ginseng (dialkoxyphenyl) phosphine, ginseng ( Trialkoxyphenyl)phosphine, para(tetraalkoxyphenyl)phosphine, trialkylphosphine, dialkylarylphosphine, alkyldiarylphosphine, and the like.

In addition, as a complex compound of an organic phosphine compound and an organic boron compound, specifically, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra(p-toluene)borate, tetrabutylphosphonium tetraphenylborate, butyltriphenylphosphonium Tetraphenylphosphonium borate, butyltriphenylphosphonium tetraphenylborate, methyltributylphosphonium tetraphenylborate, etc.

A hardening catalyst can be used individually by 1 type, or can use 2 or more types together. As a method of efficiently producing a semi-cured epoxy resin composition and a cured epoxy resin composition described later, for example, a mixture of two curing catalysts having different reaction initiation temperatures and reaction speeds between the epoxy resin and the curing agent may be used. method.

When two or more curing catalysts are used in combination, the mixing ratio can be determined according to the properties required for the semi-cured epoxy resin composition and the cured epoxy resin composition, and is not particularly limited.

When the epoxy resin composition contains a curing catalyst, from the viewpoint of the formability of the epoxy resin composition, the content of the curing catalyst is 0.5% by mass to 1.5% by mass of the total mass of the epoxy resin and the curing agent. Preferably, it is 0.5% by mass to 1% by mass of the total mass of the epoxy resin and the hardener, more preferably 0.75% by mass to 1% by mass of the total mass of the epoxy resin and the hardener.

- Inorganic filler - The epoxy resin composition may contain an inorganic filler. Using an inorganic filler tends to improve the thermal conductivity of the molded product.

Inorganic fillers can be non-conductive or conductive. By using a non-conductive inorganic filler, the risk of lowering the electrical insulation of the molded product can be reduced, and by using a conductive inorganic filler, the thermal conductivity of the molded product can be further improved. In the present invention, the "non-conductive inorganic filler" refers to an inorganic filler having a volume resistivity of 10 ¹² Ωcm or higher. On the other hand, in the present invention, the "conductive inorganic filler" refers to an inorganic filler having a volume resistivity of 10 ^{−5 Ωcm} or less.

Specific examples of the material of the non-conductive inorganic filler include boron nitride, aluminum oxide, silicon oxide, aluminum nitride, magnesium oxide, silicon oxide, aluminum hydroxide, and barium sulfate. Moreover, as a material of a conductive inorganic filler, gold, silver, nickel, copper, graphite, etc. are mentioned, for example. From the viewpoint of electrical insulation of the molded product, non-conductive inorganic fillers are preferred, among which, those selected from the group consisting of alumina, boron nitride, aluminum nitride, silicon oxide, and magnesium oxide are preferred. at least one of the Furthermore, for the reasons described in WO2013/065159 A, it is preferable to contain at least alumina.

These inorganic fillers can be used singly or as a mixture of two or more kinds. For example, although boron nitride and aluminum oxide can be used together, it is not limited to this combination.

When the epoxy resin composition contains an inorganic filler, the content of the inorganic filler in the epoxy resin composition is not particularly limited. For example, it is preferably 60% by volume to 90% by volume in the solid content of the epoxy resin composition. In the epoxy resin composition, if the content of the inorganic filler is 60% by volume or more, the thermal conductivity of the molded product tends to be improved. When the content of the inorganic filler is 90% by volume or less, the formability and adhesiveness of the epoxy resin composition tend to be further improved. From the viewpoint of improving the thermal conductivity of the molded product, the content of the inorganic filler is more preferably 65% by volume to 85% by volume in the solid content of the epoxy resin composition, and more preferably 65% by volume to 85% by volume in the epoxy resin composition. It is 70 volume% - 85 volume% in solid content.

In addition, in this specification, the content rate (volume%) of an inorganic filler is set as the value calculated|required by the following formula.

Inorganic filler content (volume %)={(Dw/Dd)/((Aw/Ad)+(Bw/Bd)+(Cw/Cd)+(Dw/Dd)+(Ew/Ed)+(Fw /Fd))}×100

Here, each variable is as follows. Aw: mass composition ratio of epoxy resin (mass%) Bw: mass composition ratio of hardener (mass%) Cw: mass composition ratio of hardening catalyst (optional component) (mass%) Dw: mass composition ratio of inorganic filler (mass%) Ew: mass composition ratio (mass%) of silane coupling agent (optional component) Fw: mass composition ratio (mass%) of other optional components Ad: specific gravity of epoxy resin Bd: specific gravity of hardener Cd: hardener Specific gravity of catalyst (optional component) Dd: Specific gravity of inorganic filler Ed: Specific gravity of silane coupling agent (optional component) Fd: Specific gravity of other optional components

When the particle size distribution curve is plotted with the particle diameter as the horizontal axis and the frequency as the vertical axis, the inorganic filler may have a single peak or multiple peaks. Using an inorganic filler whose particle size distribution curve has a plurality of peaks can further improve the fillability of the inorganic filler and further improve the thermal conductivity of the molded product.

When there is a single peak when drawing the particle size distribution curve of the inorganic filler, from the viewpoint of the thermal conductivity of the molded product, it corresponds to the particle size of 50% of the weight accumulation from the small particle size side of the weight cumulative particle size distribution of the inorganic filler That is, the average particle diameter (D50) is preferably 0.1 μm to 100 μm, more preferably 0.1 μm to 70 μm. Moreover, the inorganic filler which has a particle size distribution curve which has several peaks can be comprised, for example by combining two or more types of fillers which have different D50.

The D50 of the inorganic filler is measured by the laser diffraction method, and when the weight cumulative particle size distribution curve is drawn from a small particle size, it corresponds to the particle size of 50% weight cumulative. The particle size distribution measurement using the laser diffraction method can be performed using a laser diffraction scattering particle size distribution measurement device (for example, LS230 manufactured by Beckman Coulter).

When combining two types of inorganic fillers having different average particle diameters, examples of combinations of inorganic fillers include, for example, mixed fillers of inorganic filler (A) and inorganic filler (B). D50 is 20 μm to 100 μm, and D50 of the inorganic filler (B) is 1/2 or less of the inorganic filler (A) and is 0.1 μm to 50 μm. The mixed filler is preferably in the following proportion: when taking the total volume of the inorganic filler as the basis (100 volume %), the inorganic filler (A) is 50 volume % to 90 volume %, and the inorganic filler (B) is 10 volume % to 50 volume % (However, the total volume % of the inorganic filler (A) and the inorganic filler (B) is 100 volume %).

When combining three types of inorganic fillers having different average particle diameters, examples of combinations of inorganic fillers include: mixed fillers of inorganic filler (A'), inorganic filler (B') and inorganic filler (C') , the D50 of the inorganic filler (A') is 20 μm to 100 μm, the D50 of the inorganic filler (B') is less than 1/2 of the inorganic filler (A') and is 10 μm to 50 μm, and the inorganic filler ( D50 of C') is 1/2 or less of the inorganic filler (B') and is 0.1 μm to 20 μm. The mixed filler is preferably in the following proportion: when taking the total volume of the inorganic filler as the basis (100 volume %), the inorganic filler (A') is 20 volume % to 89 volume %, and the inorganic filler (B') is 10 volume % to 50 volume %. Volume %, inorganic filler (C') is 1 volume %～30 volume % (but, the total volume % of inorganic filler (A'), inorganic filler (B') and inorganic filler (C') is 100 volume %).

When the epoxy resin composition is applied to molded products and molded cured products described later, D50 of the inorganic fillers (A) and (A') is preferably appropriately selected according to the target thickness of the molded product or molded cured product.

In addition, the epoxy resin composition may further contain an inorganic filler whose D50 is 1 nm or more and less than 100 nm as needed.

-Silane coupling agent- The epoxy resin composition of this invention may contain a silane coupling agent as needed.

When the epoxy resin composition contains a silane coupling agent, the content of the silane coupling agent in the epoxy resin composition is not particularly limited. For example, it is preferably 0.01% by mass to 0.1% by mass in the solid content of the epoxy resin composition.

There is no particular limitation when using a silane coupling agent, but among them, a silane coupling agent having a phenyl group is preferably used. The proportion of the silane coupling agent having a phenyl group in the whole silane coupling agent is preferably at least 50% by mass, more preferably at least 80% by mass, more preferably at least 90% by mass.

The effect of containing the silane coupling agent is that the flowability of the epoxy resin composition can be improved and the thermal conductivity of the molded product can be improved by creating an interaction between the surface of the inorganic filler and the epoxy resin surrounding it. In addition, since moisture can be prevented from penetrating into the molded product, it also tends to contribute to improving the insulation reliability of the molded product. Among them, the silane coupling agent having a phenyl group can easily interact with the epoxy resin having a liquid crystal skeleton, so it can achieve more excellent thermal conductivity of the molded product. In addition, in order to make the surface of the inorganic filler close to the epoxy resin surrounding it to achieve excellent thermal conductivity of the molded product, the silane coupling agent having a phenyl group preferably contains a direct bond between the phenyl group and a silicon atom (Si) knotted silane coupling agent.

A silane coupling agent in which a phenyl group is directly bonded to a silicon atom (Si), and the proportion of the phenyl group in the silane coupling agent having a phenyl group is preferably at least 30% by mass, more preferably at least 50% by mass, and preferably at least 80% by mass The above is better.

The kind of the silane coupling agent which has a phenyl group is not specifically limited, A commercially available thing can be used. As specific examples, for example: 3-anilinopropyltrimethoxysilane, 3-anilinopropyltriethoxysilane, N-methylanilinopropyltrimethoxysilane, N-methylanilino Propyltriethoxysilane, 3-phenyliminopropyltrimethoxysilane, 3-phenyliminopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, Diphenyldimethoxysilane, diphenyldiethoxysilane, triphenylmethoxysilane, triphenylethoxysilane, etc. These silane coupling agents may be used alone or in combination of two or more.

The silane coupling agent should just be contained in an epoxy resin composition, and it may exist in the state which covered the surface of the inorganic filler, or it may exist in an epoxy resin composition independently.

The method of adding the silane coupling agent to the epoxy resin composition is not particularly limited. Specifically, there are the following methods: the integration method that is added when mixing epoxy resin, inorganic filler and other materials; the masterbatch that mixes a certain amount of silane coupling agent with a small amount of resin and then mixed with other materials such as inorganic filler method; before mixing with other materials such as epoxy resin, the inorganic filler is mixed with the silane coupling agent, and the surface of the inorganic filler is treated with the silane coupling agent in advance. In addition, there are the following methods in the pretreatment method: the dry method of dispersing the stock solution or solution of the silane coupling agent and the inorganic filler by high-speed stirring; using a dilute solution of the silane coupling agent to make the inorganic filler slurry Chemical, or impregnate the inorganic filler in the silane coupling agent, and apply the wet method of silane coupling agent treatment to the surface of the inorganic filler, etc.

The amount of silicon atoms derived from the silane coupling agent per unit specific surface area of the inorganic filler is preferably 5.0×10 ^{- 6} mol/m ² to 10.0×10 ^{- 6} mol/m ² , preferably 5.5×10 ^{- 6} mol/m 2 It is preferably m ² to 9.5×10 ^{- 6} mol/m ² , more preferably 6.0×10 ^{- 6} mol/m ² to 9.0×10 ^{- 6} mol/m ² .

The method of measuring the amount of silicon atoms derived from the silane coupling agent attached per unit specific surface area of the inorganic filler is as follows. First of all, the measurement method of the specific surface area of the inorganic filler is mainly to apply the BET method. The so-called BET method refers to a gas adsorption method, which is to make nitrogen (N ₂ ), argon (Ar), krypton (Kr) and other inert gas molecules adsorb on solid particles, and then measure the The specific surface area of a solid particle. The measurement of the specific surface area can be performed using a specific surface area pore distribution measuring device (for example, SA3100 manufactured by Beckman Coulter).

In addition, the silicon atoms derived from the silane coupling agent existing on the surface of the inorganic filler can be rotated by ²⁹ Si cross-polarization magic angle (Cross Polarization/Magic Angle Spinning, CP/MAS) solid-state nuclear magnetic resonance (Nuclear Magnetic Resonance, NMR) for quantitative determination. This CP/MAS solid-state NMR (such as JNM-ECA700 manufactured by Japan Electronics Co., Ltd.) has high resolution, so even if silicon oxide is contained in the inorganic filler, silicon atoms derived from silicon oxide as the inorganic filler can still be extracted. Distinguished from silicon atoms derived from silane coupling agents. When the inorganic filler does not contain silicon oxide, the silicon atoms derived from the silane coupling agent can also be quantified by a fluorescent X-ray analysis device (eg, Supermini 200 manufactured by Rigaku Co., Ltd.).

Based on the specific surface area of the inorganic filler obtained as described above, and the amount of silicon atoms derived from the silane coupling agent existing on the surface of the inorganic filler, the ratio of silicon atoms derived from the silane coupling agent per unit specific surface area of the inorganic filler was calculated. Adhesion.

-Other Components- The epoxy resin composition of the present invention may contain a release agent as needed. As the mold release agent, for example: oxidized and non-oxidized polyolefin, carnauba wax, octacosanoic acid ester, octacosanoic acid and stearic acid, these can be used alone or in combination. more than one species.

In addition, the epoxy resin composition of the present invention may contain stress relaxants such as silicone oil and silicone rubber powder, reinforcing materials such as glass fibers, and the like as needed.

The epoxy resin composition of the present invention can be produced by any method as long as various components can be dispersed and mixed. For example, when producing a molded product and a molded hardened product, a predetermined amount of ingredients are sufficiently mixed using a mixer, etc., melt-kneaded using a mixing roll, an extruder, etc., cooled, and pulverized. Specifically, it can be obtained by stirring and mixing a predetermined amount of the above-mentioned components, kneading using a kneader, roll, extruder, etc. previously heated to 70° C. to 140° C., cooling, pulverizing, and the like. When producing molded products and molded cured products, the epoxy resin composition is easy to use if it is tabletized with a size and quality that meet the molding conditions.

<Semi-cured epoxy resin composition> The semi-cured epoxy resin composition of the present invention is a semi-cured body of the epoxy resin composition of the present invention. The semi-cured epoxy resin composition of the present invention is derived from the epoxy resin composition of the present invention, and is obtained by subjecting the epoxy resin composition of the present invention to semi-curing treatment.

In this specification, the so-called semi-hardened epoxy resin composition means that when heated to 80°C to 120°C, the resin component will melt and the viscosity will decrease to 10 Pa‧s to 10 ⁴ Pa‧s. Semi-hardened body of resin composition. In addition, the resin component of the cured epoxy resin composition described later will not be melted by heating. In addition, the said viscosity is measured by dynamic viscoelasticity measurement (DMA) (For example, ARES-2KSTD by TA Instruments company). The measurement conditions were performed by a shear test with the frequency set to 1 Hz.

The semi-curing treatment can be performed by, for example, heating the epoxy resin composition at a temperature of 50° C. to 180° C. for 1 minute to 30 minutes.

<Cured Epoxy Resin Composition> The cured epoxy resin composition of the present invention is a cured body of the epoxy resin composition of the present invention. The cured epoxy resin composition of the present invention is derived from the epoxy resin composition of the present invention, and is obtained by curing the epoxy resin composition of the present invention. The reason why the cured epoxy resin composition of the present invention is excellent in thermal conductivity is considered to be, for example, that the epoxy resin contained in the epoxy resin composition has formed a high-order structure centering on the inorganic filler.

The cured epoxy resin composition of the present invention can be produced by subjecting an uncured epoxy resin composition or the semi-cured epoxy resin composition of the present invention to a curing treatment. The method of curing treatment can be appropriately selected according to the composition of the epoxy resin composition, the purpose of curing the epoxy resin composition, etc., but heat and pressure treatment is preferred. The hardening treatment can be carried out by the following method, for example: heating the uncured epoxy resin composition at 100°C to 250°C for 30 minutes to 600 minutes. The following method is preferred: the unhardened epoxy resin composition is made into a semi-hardened epoxy resin composition by the aforementioned method, and then heated at 100° C. to 200° C. for 1 minute to 30 minutes, and then heated at 150° C. to 250° C. ℃ heating for 60 minutes to 300 minutes.

<Molded product and molded hardened product> The molded product of the present invention is produced by press-molding the epoxy resin composition of the present invention. In addition, the molded cured product of the present invention is produced by post-curing the molded product of the present invention by heating.

The most common method of press molding the epoxy resin composition of the present invention is transfer molding. As a method of press molding, a compression molding method or the like can be used. In the present invention, the temperature of the die during press molding is preferably 100°C to 200°C, more preferably 120°C to 180°C. When the temperature of the mold is 100° C. or higher, the epoxy resin tends to dissolve during molding and molding tends to be easy. If the temperature of the mold is 200° C. or lower, the thermal conductivity of the molded product tends to increase.

According to the X-ray diffraction method using CuKα rays, the molded article obtained by the present invention has a diffraction peak in the range of a diffraction angle 2θ of 3.0° to 3.5°. A molded product having such a diffraction peak has a high-order structure, particularly a highly ordered smectic structure, and is excellent in thermal conductivity.

The epoxy resin composition of the present invention can also be used as a molded product after being removed from the mold after molding, and can also be used in the form of a molded cured product after post-curing by heating in an oven if necessary. . At this time, heating conditions can be appropriately selected according to the types, amounts, and the like of components such as epoxy resins and curing agents contained in the epoxy resin composition. For example: the heating temperature of the molding is preferably 150°C to 250°C, more preferably 180°C to 220°C. The heating time of the molding is preferably 30 minutes to 600 minutes, more preferably 60 minutes to 300 minutes.

According to the X-ray diffraction method using CuKα rays, the molded hardened product has a diffraction peak at a diffraction angle 2θ of 3.0° to 3.5° similarly to the molded product before post-hardening. This fact indicates that the highly ordered smectic structure formed in the molded product is maintained after post-hardening by heating, and a molded hardened product excellent in thermal conductivity can be obtained.

The epoxy resin composition of the present invention can be used not only in the fields of industrial and automotive engines and inverters, but also in the fields of printed wiring boards and sealing materials for semiconductor elements. [Example]

The following examples illustrate the present invention in detail, but the present invention is not limited by these examples. In addition, unless otherwise specified, "part" and "%" are mass standards.

The materials and their abbreviations used in producing the epoxy resin composition are shown below.

‧Epoxy resin

The epoxy resin monomer shown in the following structure: use 4-{4-(2,3-epoxypropoxy)phenyl}cyclohexyl=4-(2,3-epoxypropoxy ) benzoate (epoxy group equivalent: 212g/eq, production method: described in Patent Document 3) is partially reacted with a predetermined amount of hydroquinone (manufactured by Wako Pure Chemical Industries, Ltd., hydroxyl equivalent: 55g/eq) The prepolymerized compound is used as an epoxy resin.

The equivalent ratio (Ep/Ph) of the epoxy group derived from the epoxy resin monomer and the phenolic hydroxyl group derived from hydroquinone (Ep/Ph) is as follows.

Epoxy 1:100/7

Epoxy 2: 100/10

Epoxy 3: 100/13

Epoxy 4: 100/15

Epoxy 5: 100/20

<Synthesis of epoxy resin 1 to epoxy resin 5 (prepolymerization)>

Weigh 50 g (0.118 mol) of epoxy resin monomer into a 500 mL three-necked flask, and add 80 g of propylene glycol monomethyl ether therein. A cooling pipe and a nitrogen introduction pipe were installed in the three-necked flask, and a stirring blade was attached so as to be immersed in a solvent. This three-necked flask was immersed in an oil bath at 120°C, and stirring was started. After confirming that the epoxy resin monomer is dissolved and becomes a transparent solution, hydroquinone is added so that Ep/Ph becomes 100/7, 100/10, 100/13, 100/15, and 100/20, and 0.5 g of triphenylphosphine is further added , and continued heating at an oil bath temperature of 120 °C. After continuing heating for 5 hours, propylene glycol monomethyl ether was distilled off under reduced pressure from the reaction solution, and the residue was cooled until room temperature (25° C.), thereby obtaining epoxy resin 1 to epoxy resin 5, which are epoxy resins Part of the resin monomer is prepolymerized.

By comparing the molecular weight of the target compound, it was confirmed that epoxy resin 1 to epoxy resin 5 contained a compound composed of the following structure (corresponding to a dimer compound) using a UV spectrum and a mass spectrometer. The liquid chromatographic method implemented by the liquid chromatograph of the detector can be obtained. Specifically, liquid chromatography was performed using LaChrom II C18 manufactured by Hitachi, Ltd. as an analytical column, tetrahydrofuran as an eluent, and a flow rate of 1.0 mL/min. The UV spectrum detector detects the absorbance at a wavelength of 280 nm. At this time, the compound formed by the following structure can observe the peak at the position of 17.4 minutes, and the epoxy resin monomer can be observed at the position of 14.9 minutes to the peak. In addition, the mass spectrometer detects with the ionization voltage set to 2700 V, and the molecular weight of the compound composed of the following structure is 959 in the state where one proton is added.

The solid content amount of epoxy resin 1 - epoxy resin 5 was measured by the heating loss method. Specifically, it is calculated based on the following amount measurement and the following formula: the amount measured after weighing 1.0 g to 1.1 g of the sample into an aluminum cup and placing it in a dryer set at a temperature of 180° C. for 30 minutes; and Quantity measurement before heating. Amount of solid content (%) = (quantity measurement after standing for 30 minutes/quantity measurement before heating) × 100

The epoxy group equivalent of epoxy resin 1-epoxy resin 5 was measured by the perchloric acid titration method.

The content of the dimer compound composed of the above structure and the unreacted epoxy resin monomer in the epoxy resin 1 to the epoxy resin 5 in the whole epoxy resin is determined by the reaction described later. The determination was carried out by chromatography (RPLC). As an RPLC column for analysis, Mightysil RP-18 manufactured by Kanto Chemical Co., Ltd. was used. Using the gradient method, the mixing ratio (volume basis) of the eluate is continuously changed from acetonitrile/tetrahydrofuran/water=20/5/75 to acetonitrile/tetrahydrofuran=80/20 (20 minutes from the beginning) through acetonitrile/tetrahydrofuran= 50/50 (35 minutes from start) to measure. The flow rate was set at 1.0 mL/min. Detect the absorbance at a wavelength of 280 nm, and set the total area of all the detected peaks as 100, and after calculating the ratio of the corresponding peak areas, set the value as the value of each compound in the epoxy resin Content rate [mass %] in the whole. Table 1 shows the content ratios of dimers and unreacted epoxy resin monomers contained in epoxy resins 1 to 5.

[Table 1]

‧Hardener: Catechol-resorcinol novolac resin (feed ratio based on mass: catechol/resorcinol=5/95, hydroxyl equivalent: 65 g/eq)

<Synthesis of curing agent> In a 3 L separate flask equipped with a stirrer, a cooler, and a thermometer, 627 g of resorcinol, 33 g of catechol, 316.2 g of 37% by mass formaldehyde, 15 g of oxalic acid, and 300 g of water were added, And while heating in an oil bath, the temperature was raised to 100 degreeC. Reflux was carried out at around 104°C, and the reaction was continued at the reflux temperature for 4 hours. Then, while distilling off water, the temperature in the flask was raised to 170°C. The reaction was continued for 8 hours while maintaining 170°C. After the reaction, concentration was carried out for 20 minutes under reduced pressure, and water and the like in the system were removed to obtain a novolac resin which is a hardener intended. As a result of confirming the structure of the obtained curing agent by field desorption ionization mass spectrometry (FD-MS), it was confirmed that all structures represented by general formula (III-1) to general formula (III-4) exist .

In addition, the measurement of the physical property value of a hardening|curing agent was performed as follows. The number average molecular weight (Mn) and weight average molecular weight (Mw) were measured using a high performance liquid chromatograph L6000 manufactured by Hitachi, Ltd. and a data analyzer C-R4A manufactured by Shimadzu Corporation. GPC columns were G2000HXL and G3000HXL manufactured by Tosoh Co., Ltd., the sample concentration was 0.2% by mass, tetrahydrofuran was used as the mobile phase, and the measurement was performed at a flow rate of 1.0 mL/min. A calibration curve was prepared using a polystyrene standard sample, and Mn and Mw were measured using the polystyrene conversion value.

The hydroxyl equivalent is determined by acetyl chloride-potassium hydroxide titration. Furthermore, since the color of the solution is dark, the determination of the titration end point is not performed by the colorimetric method using an indicator, but by potentiometric titration. Specifically, after acetyl chlorination of the hydroxyl group of the phenolic resin with acetyl chloride in a pyridine solution, the excess reagent is decomposed with water, and the generated acetic acid is titrated with potassium hydroxide/methanol solution , and the determination of hydroxyl equivalents. The physical property values of the hardener are as follows.

The hardener is a novolac resin composition, which contains a novolac resin (hydroxyl equivalent: 65 g/eq, Mn: 422, Mw: 564), and the novolac resin is a composition having the general formula (III-1) to the general formula A mixture of compounds with at least one structure represented by (III-4), wherein Ar ³¹ to Ar ³⁴ are R ³¹ ═OH and R ³² ═R ³³ ═H in the general formula (III-a), that is, derived from 1 , 2-dihydroxybenzene (catechol) group and 1,3-dihydroxybenzene (resorcinol)-derived group, and contains 35% of monomer components (resorcinol) as a low molecular weight thinner.

‧Hardening catalyst: Triphenylphosphine (manufactured by Beixing Chemical Industry Co., Ltd.)

‧Alumina filler AL35-63 (alumina made by Micron, average particle size 50 μm, specific surface area 0.1 m ² /g) AL35-45 (alumina made by Micron company, average particle size 20 μm, specific surface area 0.2 m ² /g) g) AX3-32 (Alumina manufactured by Micron, average particle size 4 μm, specific surface area 1.0 m ² /g)

‧Silane coupling agent: KBM-573 (3-phenylaminopropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.)

‧Release agent: Licowax E (Octadecanoate, manufactured by CLARIANT Japan Co., Ltd.)

‧Molding and forming hardening method: After mixing and kneading a predetermined amount of epoxy resin, hardener, hardening catalyst, inorganic filler, silane coupling agent and mold release agent, use a transfer molding machine at a pressure of 20 MPa 1. The resulting kneaded product was molded into a width of 10 mm x length of 80 mm x thickness of 3 mm under the condition of a temperature of 140° C. to obtain a molded product. Then, post-hardening was performed at 180° C. for 5 hours to obtain a molded hardened product.

‧Evaluation method: <Measurement of the adhesion amount of silicon atoms derived from silane coupling agent per unit specific surface area of inorganic filler> Measure inorganic The specific surface area of the filler. Then, silicon atoms derived from the silane coupling agent existing on the surface of the inorganic filler were quantified by ²⁹ Si CP/MAS solid-state NMR using a nuclear magnetic resonance apparatus (NMR, manufactured by JEOL Ltd., JNM-ECA700). The adhesion amount [mol/m ² ] of the silicon atoms derived from the silane coupling agent per unit specific surface area of the inorganic filler was calculated from the values thus obtained.

<Measurement of the flow distance of the kneaded product> The kneaded product was molded under the above conditions using a mold for measuring spiral flow according to EMMI-1-66, and the flow distance [cm] thereof was obtained.

<Measurement of Thermal Conductivity of Molded or Formed Hardened Product> After the molded or shaped hardened product was cut into 10 mm squares and blackened by graphite spray, the Xenon flash method (manufactured by NETZSCH, LFA447 nanoflash) was used. Thermal diffusivity [m ² /s] was evaluated. The thermal conductivity [W/(m‧K)] was obtained by multiplying the density [g/cm ³ ] and the specific heat [J/(g‧K)] by the obtained thermal diffusivity. In addition, the density uses the value measured by the Archimedes method, and the specific heat uses the value measured by the differential scanning calorimeter (DSC) (Pyris1 by PerkinElmer).

<Measurement of the glass transition temperature (Tg) of the molded or molded hardened product> The molded or molded hardened product was cut into a width of 5 mm x length of 50 mm, and a dynamic viscoelasticity measuring device (RSA-G2 manufactured by TA Instruments) was used, Using a three-point bending vibration test fixture, the dynamic viscoelasticity was measured within the temperature range of 40°C to 300°C under the conditions of a frequency of 1 Hz and a heating rate of 5°C/min. In tan δ obtained from the ratio of the storage elastic modulus to the loss elastic modulus thus obtained, the temperature at the peak top portion was defined as Tg [° C.].

<Judging whether the resin forms a smectic structure> X-ray diffraction (XRD, manufactured by Rigaku Co., Ltd., wide-angle X-ray diffraction device ATX-G) is performed on the molded product or molded cured product. CuKα rays were used as the X-ray source, the tube voltage was set to 50 kV, the tube current was set to 300 mA, and the scanning speed was set to 1°/min. When the diffraction peak appeared within the range of the diffraction angle 2θ of 3° to 3.5°, it was judged that the resin had formed a smectic structure.

Table 2 below shows the composition and evaluation results of each kneaded product. In addition, in Table 2, "8.9E-06" indicated in the column of "Amount of attached silicon atoms ^{derived from a silane coupling agent" means 8.9×10 −6 .}

[Table 2]

From the results in Table 2, it can be seen that in Examples 1 to 3, the proportion of the specific dimer compound of the present invention in the entire epoxy resin is 15% by mass to 28% by mass, and the flow distance is relatively large, while the moldability excellent. In addition, good results were also obtained in thermal conductivity and glass transition temperature (Tg).

It can be seen that in Comparative Example 1, the ratio of the specific dimer compound of the present invention to the entire epoxy resin is less than 15% by mass, the flow distance is small, and the formability is insufficient.

In addition, in Comparative Example 2, the proportion of the specific dimer compound of the present invention in the entire epoxy resin exceeds 28% by mass, and the glass transition temperature (Tg) is insufficient although the flow distance is large.

Furthermore, this case is to quote the disclosure contents of Japanese Patent Application No. 2016-034886 filed on February 25, 2016 and PCT/JP2016/074879 filed on August 25, 2016 by reference. in this manual. All documents, patent applications, and technical specifications described in this specification are specifically incorporated in this specification by reference to each document, patent application, and technical specification to the same extent as they are separately described.

Domestic deposit information (please note in order of depositor, date, and number) None

Overseas storage information (please note in order of storage country, institution, date, number) None

(Please write separately on another page) None

Claims (17)

An epoxy resin composition, which contains an epoxy resin and a hardener, the aforementioned epoxy resin includes a polymer compound, and the polymer compound has a structural unit selected from the following general formula (IA) and the following general formula At least one of the group consisting of structural units represented by (IB), the aforementioned polymer compound includes a dimer compound having two structures represented by the following general formula (II) in one molecule of the dimer compound unit, and the proportion of the aforementioned dimer compound in the aforementioned epoxy resin as a whole is 15% by mass to 28% by mass; the aforementioned epoxy resin includes an epoxy resin monomer represented by the following general formula (I"), and The proportion of the aforementioned epoxy resin monomer in the aforementioned epoxy resin as a whole is 57% by mass to 80% by mass;

In the general formula (IA) and the general formula (IB), R ¹ ~ R ⁴ each independently represent a hydrogen atom or an alkyl group with 1 to 3 carbons, R ⁵ each independently represent an alkyl group with 1 to 8 carbons, n represents an integer from 0 to 4;

In the general formula (II), R ¹ ~ R ⁴ each independently represent a hydrogen atom or an alkyl group with 1 to 3 carbons;

In the general formula (I"), R ¹ to R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbons. The epoxy resin composition as claimed in claim 1, wherein the aforementioned dimer compound comprises a compound represented by the following general formula (II-A), a compound represented by the following general formula (II-B) and the following At least one of the group consisting of compounds represented by the general formula (II-C), and the compound represented by the following general formula (II-A), the compound represented by the following general formula (II-B) and the following The total amount of the compound represented by the general formula (II-C) accounts for 15% by mass to 28% by mass in the aforementioned epoxy resin as a whole;

In general formula (II-A) ~ general formula (II-C), R ¹ ~ R ⁴ each independently represent a hydrogen atom or an alkyl group with 1 to 3 carbons, R ⁵ each independently represent a carbon number 1 to 8 The alkyl group, n represents the integer of 0~4. The epoxy resin composition as claimed in claim 1, wherein the aforementioned structural unit represented by general formula (IA) is a structural unit represented by following general formula (IA') and the aforementioned structure represented by general formula (IB) The unit is a structural unit represented by the following general formula (IB');

In general formula (IA') and general formula (IB'), R ¹ ~ R ⁴ each independently represent a hydrogen atom or an alkyl group with 1 to 3 carbons, R ⁵ each independently represent an alkane with 1 to 8 carbons Base, n represents an integer from 0 to 4. The epoxy resin composition according to claim 3, wherein the dimer compound is selected from a compound represented by the following general formula (II-A') and a compound represented by the following general formula (II-B') and at least one of the group consisting of compounds represented by the following general formula (II-C'), and the compound represented by the following general formula (II-A'), represented by the following general formula (II-B') The total amount of the compound represented and the compound represented by the following general formula (II-C') accounts for 15% by mass to 28% by mass of the epoxy resin as a whole;

In general formula (II-A') ~ general formula (II-C'), R ¹ ~ R ⁴ each independently represent a hydrogen atom or an alkyl group with 1 to 3 carbons, R ⁵ each independently represent a carbon number 1 An alkyl group of ~8, and n represents an integer of 0~4. The epoxy resin composition as described in any one of claim 1 to claim 3, wherein the aforementioned hardener comprises a novolak resin, and the novolak resin comprises a compound having a compound selected from the following general formula (II-1) and A compound of at least one structural unit represented by the group formed by the following general formula (II-2);

In general formulas (II-1) and (II-2), R ²¹ and R ²⁴ each independently represent an alkyl group, an aryl group or an aralkyl group, and R ²² , R ²³ , R ²⁵ and R ²⁶ each independently represent A hydrogen atom, an alkyl group, an aryl group or an aralkyl group, m21 and m22 each independently represent an integer of 0 to 2, and n21 and n22 each independently represent an integer of 1 to 7. The epoxy resin composition as described in any one of claim 1 to claim 3, wherein the aforementioned hardening agent comprises a novolac resin, and the novolak resin comprises a compound having a compound selected from the following general formula (III-1)～ A compound of at least one structure represented by the group formed by the following general formula (III-4);

In general formula (III-1) ~ general formula (III-4), m31 ~ m34 and n31 ~ n34 each independently represent a positive integer, Ar ³¹ ~ Ar ³⁴ each independently represent the following general formula (III-a) Any one of the groups represented by and the groups represented by the following general formula (III-b);

In general formula (III-a) and general formula (III-b), R ³¹ and R ³⁴ each independently represent a hydrogen atom or a hydroxyl group, R ³² and R ³³ each independently represent a hydrogen atom or a carbon number of 1 to 8 alkyl. The epoxy resin composition according to claim 5, wherein the curing agent contains a monomer constituting the novolac resin in an amount of 10% by mass to 50% by mass, and the monomer is a phenolic compound. The epoxy resin composition according to claim 6, wherein the curing agent contains a monomer constituting the novolak resin in an amount of 10% by mass to 50% by mass, and the monomer is a phenolic compound. The epoxy resin composition according to any one of claim 1 to claim 3, further comprising an inorganic filler. The epoxy resin composition according to claim 9, wherein the material of the aforementioned inorganic filler contains at least one selected from the group consisting of alumina, boron nitride, aluminum nitride, silicon oxide, and magnesium oxide. The epoxy resin composition as described in Claim 9, wherein, In solid content, the content rate of the said inorganic filler is 60 volume% - 90 volume%. The epoxy resin composition according to any one of claim 1 to claim 3, further comprising a silane coupling agent. The epoxy resin composition according to claim 12, wherein the aforementioned silane coupling agent includes a silane coupling agent having a phenyl group. A semi-hardened epoxy resin composition, which is a semi-hardened body of the epoxy resin composition described in any one of claim 1 to claim 13. A cured epoxy resin composition, which is a hardened body of the epoxy resin composition described in any one of claim 1 to claim 13. A molded article produced by press-molding the epoxy resin composition described in any one of claim 1 to claim 13. A molded hardened product obtained by post-curing the molded product described in claim 16 by heating.